The latest round of talks come as Russia and Ukraine exchanged overnight strikes.
Kyiv's military administration chief, Tymur Tkachenko, said a fire had broken out at a high-rise residential apartment building in the Dniprovskyi district, forcing the evacuation of its residents.
Emergency services on the scene said 18 people had been rescued, including three children, and the search for victims was ongoing after the fire had been contained.
Residents of a high-rise apartment in the city's central Pechersk district were also evacuated after it was set ablaze during the strikes according to Kyiv's mayor Vitali Klitschko.
He added that the building suffered damage to the upper floors, but the fire had been extinguished.
Ukraine's air defence units responded to the attack as explosions were heard across Kyiv and residents were urged to take shelter in underground car parks and bunkers.
Ukraine's Ministry of Energy also confirmed a "massive, combined enemy attack" on the country's energy infrastructure facilities.
According to Zelensky, 22 missiles and more than 460 drones were launched at Ukraine overnight.
Nato scrambled four planes over Romania - the third time in four days its planes have been sent to intercept drones in Ukraine's border region. Six Russian drones were also detected in Moldova.
Meanwhile, the Russian defence ministry said it had intercepted 249 Ukrainian drones overnight, including over the Black Sea and Kursk.
In Russia's Rostov region, the death toll from a Ukrainian strike had risen to three, after initial reports of one death, officials said.
According to Russia's acting governor of the Rostov region Yuri Sliusar, two died in hospital.
One of the deaths was reported in the city of Taganrog, where mayor Svetlana Kambulova vowed "necessary response measures".
Another 10 people were injured in the strikes.
In the southern Krasnodar region, Governor Veniamin Kondratyev described Ukraine's overnight bombardment "one of the Kyiv regime's most sustained and massive attacks".
